Group kennels and daycare-style boarding often use shared yards, shared walls and shuffled schedules. Ask each host what physically keeps dogs apart, including during arrival, pick-up, walks and garden time.
A suitable setup may use a room or annex for the guest dog, garden time on a solo schedule, and walks routed away from busy paths or skipped in favor of decompression at home. Check the confirmation label and verify the details with the host.
If your dog needs medication or a fixed routine, ask the host directly how they would handle it before you book.