How to show fewer instruments at start of flow.. more later

i have an orchestral score which starts out with just brass and would like to show just those instruments until i add other sections. Is there a way to do this, or it this just multiple flows in the same movement?

Layout options >Vertical spacing > Hide empty staves should do the trick in page view. To customize what you see in galley view, use the instrument filter tool added in Dorico 4