The source is oriented along the Z axis, but suppose we want to orient it along the X axis; we would need to rotate the source object by 90 degrees about the Y axis. Enter 90 for the Tilt About Y parameter of the source.

The default YZ plane view of the layout show the filament being oriented along the X axis, however, the XZ plane view reveals that the filament is shifted towards +X axis. To rotate the layout, change the layout view angle in the Layout settings window (click Settings in the Layout menu). You can also rotate the drawing by pressing the left, right up down arrow key and Page Up and Page Down key on your keyboard.

The reason for the decenter is because the rotation axis of the Source Filament is not at the center of the object but at the end. To center the source in the X axis, enter -10 in the X position column.

Update the layout and it will now show the desired filament location and orientation.