Subform with a many to many relation.

I've got a form where I want to show a subform with all the related records.
I've got 3 tables: Table1, Table2 and Table1-Table2
In table one I've got field1(pk), field2,field3,...
In table two I've got a similar setup: 2field1(pk),2field2,2field3,...
In table 1-2 I've got the combination of the pk: field1(pk),2field1(pk)

How can I show the related records of the main form's record (based on table1) in the subform (based on table2)
while defining the relation via table 1-2?

Solved: New function in subform with parameter which contains table1.field1,
function(parameter Code[10])

Table1-2.SETRANGE(table1-2.field1,Parameter);
gv_Filter:='=';
IF Table1-2.FINDSET THEN BEGIN
  REPEAT
    gv_Filter += FORMAT(Table1-2.field2) + '|';
  UNTIL Table1-2.NEXT =0;
  gv_Filter := DELSTR(gv_Filter,STRLEN(gv_Filter));
  SETFILTER(Table2.2field1,gv_Filter);
END ELSE
  SETRANGE(Table2.2field1,' ');

CurrForm.UPDATE(FALSE);

In the main form on the aftergetcurrRecord
CurrForm.SubFormID.FORM.function(table1.field1)