to access Combine Path, then select the entities to modify.Right click Explode to access Combine Path, then select the entities to modify.
COMBINE joins two paths to make a single path. The two paths needn’t share endpoints.
The prompt reads "Select first path:" Choose the first path of the two you want to combine.
The prompt reads "Select second path:" Choose the second path of the two you want to combine.
Click to complete the command, right click to cancel, or press F or S to swap the nodes of the joining segment.
You now have a single path entity.