How to regroup model downloaded from 3d warehouse

I downloaded model from 3d warehouse and set to modify it, the problem is it’s pretty much group together. For example, I wanted to hide the roof so I can view the interior but the person who built it apparently didn’t ground the ceiling it’s all in one group.
I would like to re-group things so it works the way I want it.
anyone?
thanks

without a link to the file, it’s very hard to give simple advice…
If the roof has a unique material you can use ‘Right Click’ > ‘Select All with Same Material’ then ‘Right Click’ > ‘Select Bounding Edges’ > ‘Right Click’ > ‘Make Group’ then ‘Cut’ > click outside the group > ‘Paste in Place’…
add a roof ‘Layer’ and you can turn it on/off from ‘Layer Panel’

Hi there,
Thank you, I will give it a try, anyhow here is the link to the model

Thanks

adding a ‘Section Plane’ or two, may be the easiest with that model…

Hi,
If I want to have the grey areas as a part of the roof, will it be possible, when I click it the entity info shows that it has different numbers, as show in the attached picture
Thanks again
Petom

The way to select that ‘grey’ ceiling is ‘Front View’ + ‘Parallel Projection’ + ‘Box Select’ using mouse, make it a group and add to the roof layer, so it turns off as well…

the additional ones need to selected individually as it’s the default color and not a Material…

Thank you, so far it works pretty good.