No, this is what the ‘Offset Fill’ does for you based on the settings as described in the documentation I shared. Any shape you set to ‘Offset Fill’ or the ‘Fill’, and ‘Fill+Line’ layer settings will fill the shape for you based on the ‘Line Interval’ / ‘DPI’ / ‘Lines per inch’ settings when you ‘Preview’ or run the job.
You do not need to pre-fill your art to have the shape cut using a fill pattern of your choosing.
Above, I show 3 50mmx50mm squares, drawn in LightBurn. Each set to a different layer fill mode with different Line Interval spacing.
Are these shapes in a group by chance? When the shape is selected, you can tell by the look of the marquee marching ants, if you will. When you see a ‘dot-dot-dash’ pattern, that indicates the shape is a member of a group. Just dashes means it is not part of a group.
You should be able to ‘Group’ and ‘Ungroup’ within LightBurn using the icons at the top-center or by using the hotkeys ‘Ctrl + G’ to group the selection and ‘Ctrl + U’ to ungroup the selection.
Is this what you are asking?
You should be able to select a shape, multiple shapes and / or groups of shapes and assign them to a different layer. Is this not working for you?