From your Trackers view:

1. Click Columns above.
2. Click Add Column.
3. From the dropdown list select Permissions.
4. Name your Permissions column.
5. Click Save.
6. Locate the new Permissions column.
7. Click the cell corresponding to the Target company row where you want to restrict access.
8. Toggle on Restrict Row Access.
   1. Click the gear icon.
   2. Type or select a Team or a User.
   3. Click Done.

Only that User or Team and all Project Admins can see that row.