How to see collider gizmo of "unselected" objects?

I am trying to place walls into the scene that must be aligned with the nodes that have a box-collider as a trigger. When the nodes are selected, I can see the trigger gizmo, so I know where to place the walls


When I select a wall, I can not see the nodes’ colliders gizmos.

Is there a way I can set an “unselected” object from the hierarchy as “selected” without actually selecting it, just to view the objects gizmos in scene view?

Edit: Even better solution is

void OnDrawGizmos()
{
    Gizmos.color = Color.green;
    Gizmos.DrawWireCube(transform.position, transform.lossyScale);
}

Previous answer:

Well one work-around to visualize where the nodes are was to add a mesh renderer (w/ material) and mesh filter (in my case cube) to all the nodes. Notice that the collider is sized down so that the nodes don’t touch, but the mesh isn’t and can’t, unless I scaled it as a whole.
Other answers still appreciated.