I don't think the functionality exists. There's a slight workaround, and it's not perfect, but it's sort of possible.
- Create a Report Report and add a column for "Shared With" (depending on how many reports you have in the system, you may need to try and add additional filters to narrow down your results). Once your report loads, click the filter icon (the funnel) in the upper right to filter the page.
- Type the name of the group that you want to adjusting sharing permissions for.
- If you know which reports SHOULD have manage access and it's only a few, I'd recommend just bulk selecting all of the reports and re-sharing them with "View" access. Then going back and manually enhancing the ones that need "Manage" access.