VLOOKUP/MATCH With Multiple Matches

Question

I'm at a loss for how to do something which I imagine one of you gurus has done before and shouldn't be too challenging. I have two sheets in my workbook (Let's call them ITEMS and LOCS). Sheet ITEMS has a list of unique items in column A (roughly 10,000) and sheet LOCS has the items in column A and their locations in Column B. Now the issue arises since many items have multiple locations (up to five) and thus occupy multiple rows on the LOCS sheet. Is there a way to use some combination of VLOOKUP or MATCH in column B on my ITEMS sheet to get all the locations into one cell separated by a comma space. Obviously, if I put =VLOOKUP($A:$A, LOCS:$A,$B,2,0) into cell ITEMS.B1 it will only return the first location, Ideally: I would want it to display something like this, Shelf, Desk. Floor. Any ideas or pointers in the right direction would be greatly appreciated--thanks so much!

Sample Data (Columns A:B from sheet ITEMS and columns D:E are from sheet LOCS and I highlighted the desired outcome in col B in green)

Answer 1

If you have access to the new Dynamic Array Formulas you can use the following equation and drag down as needed:

Cell E2: =TEXTJOIN(", ",TRUE,FILTER(B2:B14,A2:A14=D2))

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Answer 2

If you are using Office 365 then you're in for a treat!

Here's my LOCS table -

And the array formula using TEXTJOIN (make sure to use Ctrl+Shift+Enter ) -

=TEXTJOIN(", ",1,IF(LOCS:$A$2,$A$10=A2:LOCS,$B$2:$B$10,""))

The result -