Convert line-like curve into line

hi (22.2 KB)

i have a curve that i have an offset of that curve . the result of the offset curve component is a line-like curve , i want to join other lines with this line-like curve and then i wanted to move them in a series vertically . but i does not work because one segment of this thing is a line-like curve . i will provide you the definition .
i will appreciate any help .

i just find out that i should have flatten the input of join curves component .