Filtering one table from another table's Selected Value

Here's what I came up with.  PBIX file is attached below.  

Used Power Query to parse out the #'s from your table 2, since that is what will be searched for based on the user selection from table 1.  Too much to list out here and much easier to see step by step in PQ.  But the final table:

You were on the right track with the selected value, so stuck with that:

Col 1 Selected Value = SELECTEDVALUE(Table1[Column1],0)

I used that value and searched in our newly created "Just Numbers" column from above:

Contains = 
SEARCH(
    [Col 1 Selected Value],
    MAX(Table2[Just Numbers]),,BLANK()
)

PBIX file: https://1drv.ms/f/s!AoQIGRpzoxRH0y64D4Ue5nYGNGbj