The different views on Site Manager is useful for quickly filtering and finding the content you are interested in. However, Site Manager does not show the actual URL when you change the view, which makes it difficult to restrict or redirect the user to a view (either the default one or a custom one you created).
This can actually be achieved by specifying the query string parameter “rptmode” (without the quotes) with the index of the view you wish to see.
For example, the default “Pending Approval” view has the index 3, so the URL would be: http://[site]/_layouts/sitemanager.aspx?rptmode=3
The index is the ID of the view (CAML query) in the Content and Structure Reports list (under View All Site Content).
A quick way to find out the view index is via Site Actions -> View Reports -> [select the report you want], and you will be redirected to Site Manager with the full URL displayed.