Branch

Right click in your scene view to bring up the generic menu where you get acces to branch editing actions.

Add

To add a new branch, select a node from your scene view and click "Add" in the items menu,
the selected node will be considered as the origin of the newly created branch.

Delete

To delete a branch, first you select the branch you want to delete then use the "Delete" action in the branch section of the items menu.

Weld

It is done through adding nodes to branch forks, Node=>Add=>Forks
This time you target the already existing nodes that you want your branch to form a bridge with, see image bellow for better understanding

Reverse

Reverse the direction of the branch selected.