DAX

Hi Dhruvan, here is DAX solution. However I personally prefer to go for "Text Filter" visual suggested by mlsx4 . Good luck!

Partial search measure = 
VAR _FullSearchTerm = SELECTEDVALUE( 'Selected value'[Column1] )                //here we capture selected value, remember that only 1 value at a time should be selected, otherwise use iferror argument of SELECTEDVALUE()
VAR _NumberOfCharactersToSearch = 11                                            //change number to change number of characters you're interested in
VAR _RealSearchTerm = LEFT( _FullSearchTerm, _NumberOfCharactersToSearch )      // Assumption: first N left characters

RETURN 
    IF(
        CONTAINSSTRING( 
            SELECTEDVALUE( 'Related value'[Column1] ),
            _RealSearchTerm
        ),
        1,
        0
    )