This article should help you with how to use advanced permissions in your data room
To share specific folder in your data room, you will want to open your data room and click Sharing toward the bottom left of your screen. Once you have opened your sharing settings, you will want to be under the Invited users tab.
Enter an email address and click on the dropdown underneath Can access. Select the folders in the Data room you want this contact to be able to access and click Send invite. The investor will be able to access the folders you selected to share with them. See screenshots below of examples of these pages
Open your data room and click Sharing in the bottom left
Enter the email address you want to share the data room with and select the folders you want them to access under Can access
Once those are selected, click Send invite
Let us know if you have any questions when sharing your data room.