So to summarize what i want:
Let's say i have
   A         B
1 "Tommy"    "1,2,3"
2 "Berry"    "3,4,5"
3 "Hank"     "1,4,5"
4
5
6 "1"        
7 "5"

I would like B6 to show "Tommy Hank" and B7 to show "Berry Hank"
If have managed to create this formula;
=IF(ISERROR(MATCH($A6,SPLIT(B1, "," , 1,1),0)),"",A1)

This formula will give me back the value "Tommy" but not Hank.
I want to list all corresponding A values for every B cell that contains the value "1".
I tried some things with arrayformula like =IF(ISERROR(MATCH($A6,SPLIT(B1:B3, "," , 1,1),0)),"",A1:A3) but i don't really understand what i'm doing here.

Repeat a formula in google sheet within a single cell using different values
I was going to suggest
=ArrayFormula(
   textjoin(" ",,
     query(
       {A$1:A$3,","&B$1:B$3&","},
       "select Col1 
        where Col2 contains'"&","&A6&","&"'"
     )
   )
 )


