Show the common/same/duplicates values from set of multiple rows

Hello, how best do I go about to output common/same values (from a particular array of columns:

eg:

GP1 LP-A LP-B LP-C LP-D
GP2 LP-C LP-D LP-E LP-F
GP3 LP-C LP-D LP-G LP-H

Desired Output to show when GP1+GP2+GP3 are selected (or favourited/bookmarked):
Common values in those 3 rows would be:
LP-C
LP-D

And when I have figured out the spreadsheet part, how to do i best do the component in Data Editor/Glide App itself…

thank you…