Thanks @zipit,
Managed to solve it thanks to you.

@zipit the reason why I have to use GROUP for every row is because at every row I am adding a popup button. And I can not add it using res file. So I can't do this without a group which tells me where to add the popup button.

Hello,
I have a resource file where I define the UI of materials attributes.

GROUP COATING_LAYER
{
     GROUP THICKNESS_GROUP
     {
	COLUMNS 2;
	REAL COATING_LAYER_THICKNESS{SCALE_H; MIN 0; MAX 1; MINSLIDER 0; 
        MAXSLIDER 1; STEP 0.001; CUSTOMGUI REALSLIDER;}
	SHADERLINK COATING_LAYER_THICKNESS_SHADER{ANIM ON; SCALE_H; HIDDEN;}
     }

     GROUP COLOR_GROUP
     {
	COLUMNS 2;
	COLOR COATING_LAYER_COLOR{SCALE_H;}
	SHADERLINK COATING_LAYER_COLOR_SHADER{ANIM ON; HIDDEN;}
     }
//...Continues with other groups
}

One parameter of the group I specify on the res file as above (The hidden one is not used at all in the UI) and the second parameter I specify using Description object as below.

const DescID* singleid = dc->GetSingleDescID();

	if (!singleid || ((DescID)id).IsPartOf(*singleid, NULL))
	{
		BaseContainer bc = GetCustomDataTypeDefault(DTYPE_POPUP);

		//  Set CycleButton properties
		bc.SetBool(DESC_ANIMATE, false);
		bc.SetInt32(DESC_CUSTOMGUI, CUSTOMGUI_POPUP);
		bc.SetBool(DESC_GROUPSCALEV, TRUE);
		//  Create CycleButton
		return dc->SetParameter(DescLevel(id, DTYPE_POPUP, 0), bc, groupid);
	}

	return TRUE;

The view that I get is the picture below but as you can see the paramters (Thickness, Color, Roughness etc) are not aligned as they normally do when using description resource.
How would the code or res file look like so I can have them aligned.

Hello. I am creating my own custom parameter.

I found the solution. Seems that I had to use MSG_DESCRIPTION_POPUP message to fill the popup field.

Hello. I am creating a parameter description with a popup field but I can not add childs to it. I know that in a GeDialog it is very straightforward AddChild(pop_up_ID,id,name).
Also I managed to add child to a CycleButton CustomGui and I thought it would be very similar to this.

BaseContainer bc = GetCustomDataTypeDefault(DTYPE_LONG);

bc.SetInt32(DESC_CUSTOMGUI, CUSTOMGUI_CYCLEBUTTON);
bc.SetString(DESC_NAME, "Cycle Button");
bc.SetContainer(DESC_CYCLE, settings);
return dc->SetParameter(DescLevel(id, DTYPE_LONG, 0), bc, group_id);

where settings is the container that contains the item names for the cycle.
What would be the equivalent of this for a popup field?
I have tried some options but none of it worked. Also DESC_CYCLE would not work for the items of an popup field.

BaseContainer bc = GetCustomDataTypeDefault(DTYPE_POPUP);

bc.SetInt32(DESC_CUSTOMGUI, CUSTOMGUI_POPUP);
//bc.SetString(DESC_NAME, "Pop Up Button");
//bc.SetContainer(DESC_CYCLE, settings);
return dc->SetParameter(DescLevel(id, DTYPE_POPUP, 0), bc, group_id);

Thank you.

Thank you for the help @m_magalhaes

Hello @m_magalhaes.
Thank you for your help. I understand it and I tried it, works fine.
But what if I am using GeDialog class instead, that is being called using a CommandData. How can I store the changes on that GeDialog the same way you did here?
Is this method with the WorldContainer() used only for the preferences dialog box, because GetDDescription, GetDParameter and SetDParameter functions are not part of GeDialog class.
Thank you again.

Hello @m_magalhaes
Yes I am asking for a plugin that I am creating and it is a dialog box.
So once again what I am trying to do is that after changing the settings in this dialog box (changing value of the dropdown for example) that new value will now be the dafult value of that dropdown even after restarting c4d with a different scene.
Sorry for not tagging the language that I am using but seems that when I have the bookmarks bar shown on my browser(chrome) it covers c++ tag and there is no way of selecting it without removing the bookmarks bar as the tags are unscrollable.

Hello everyone,
I wanted to have some settings which will behave as "global" parameters. What I mean is that after I change one of these parameters it will remain changed even after I close and reopen Cinema4D and even if the file is not being saved. If I use "save as default scene" It will store all the changes, including the ones in the scene which is not what I am looking for.
I just want to do this for only some settings in a GeDialog UI. Is it possible to do this?
Thank you.