An interior segment of a connection can be moved by dragging it with the mouse in a direction that is perpendicular to the segment. A segment of a connection is a straight part of a connection and can be either horizontal or vertical. An interior segment is a segment that is not attached to a block instance. Notice that only interior segments can be moved, since segments that are attached to a block have their positions fixed by the positions of the port instances.
When the mouse cursor is over a segment that can be moved, it will change from the ordinary arrow to a small double-ended arrow that is either horizontal (for vertical segments, indicating it can be moved horizontally) or vertical (for horizontal segments, indicating it can be moved vertically).
It is not possible to add or remove segments to the connection. The schematic editor will always minimize the number of segments of a connection, given the positions of its port instances and the directions in which they emerge from the port instances.