Hi. I was wondering how to set the members of a group by dragging and selecting in the viewport. This has got to be easy but I can't seem to get it to work. Thanks for the help.

Two ways. With mouse in the viewport you can Tab add group then simply box select what you want to group and then right click to finsih, or you can wire a group sop to your network and with it selected mouse into viewport hit enter and select the icon at the bottom of the vertical menu left of the viewport that has the red arrow which will ‘Reselect geometry for current operation’, then box select what you want to group then right click to finish.

or first select the things you want to group in the viewport and when it's highlighted (yellow) you TAB -> Group and then your selection is grouped. If you select points/vertices from different geometry than automagically a merge sop is added…just give it a shot!

thanks so much. much appreciated.