Chain Tool
Ribbon menu → Bodeis Tab → Booleans container → Chain Tool 
or
(Classic) Build → Bodies/Geometry → Chain Tool
Links together wire Construction geometry to create a complex profile, which you can then extrude. The geometry to be chained together must touch at one endpoint and cannot be closed geometry.
The Chain tool adds the final chained geometry to the part that owns the first geometry that you selected
Note: | If you want to use the chained geometry with a pin-in-slot or curve-to-curve constraint, you must turn the geometry into a spline. See the Spline Tool. |
Learn about Chaining Wire Geometry.