Subdomain to mask a subdirectory

newsubdomain.domain[dot]com that displays…

domain[dot]com/brand/special-page

*When goto newsubdomain.domain.com
it stays in browser. does not forward.

when goto domain[dot]com/brand/special-page - nothing masked.

Code for a Worker? Or is there an easier solution?

newsubdomain.domain.com that displays…
domaincom/brand/special-page

*When goto newsubdomain.domaincom
it stays in browser. does not forward.

when goto domaincom/brand/special-page
nothing masked.