You can move child actors by selecting them in the hierarchy on the right side of the editor. The picture below shows the hierarchy list for example.
In this picture, I am able to move the mesh, which is a child of the CapsuleComponent instead of moving the CapsuleComponent itself. Please remember however, as it is a child this will simply create an offset between the two items as the child will still replicate any movement made by the parent.
Can you show me an example of what is grayed out? Unless you have an option toggled on that is locking the transform to the parent, it should be possible to modify it to create an offset.
The blueprint actor contains a camera and box collider, and I want to move the camera only, but it seems the editor can only allow me to move it individually in blueprint.
The reason you’re unable to move the camera outside of the blueprint is because you added the camera to the object from the blueprint editor. This make it a ‘Blueprint component’ which is inherited from the class, meaning it can only be edited in blueprint.
If you wish to be able to move the camera in the default viewport, you’ll first need to remove it while in the blueprint editor, and then add it from the default viewport using the ‘Add Component’ button. Please note however, the camera will not be editable in the blueprint if done in this way.