Yes you can create a line,
Could you please tell what kind of line do you want to create reference line or normal line as others that showed in screenshot.
Similar line as shown above.
Requirement: if i select the Category filter the specific category line along with its the brand lines from the Brand filter from selection.
Could you please share the sample workbook (.twbx)
I havent created any its just a thought.
You can use the sample.
To make it more simpler , lets say we have 2 dimensions one is Country and other one State
Now i want see the line which can show me Country and its states in a single dimension which can also act as filter.