Users must create a concept set first before adding concepts; cannot start from search and build one directly.

In legacy application, you were able to go from exploring vocabulary to building a new concept set expression. This is seen in the following screenshot:

Note: in this mode, there is no other concept set open (from a cohort definition, for example) so you are given the option to add the selected concepts into the concept set with the selected options (exclude/descendants/mapped).

Users have asked to be able to create a concept set directly from searching vocabulary without having to navigate to 'new concept set' first.