There are a few ways by which you can allow your members to book a match for longer than a standard booking slot. This is especially needed for tennis matches as they can take over an hour and booking slots are typically set up on a half-hourly basis.
You first need to switch on the capability by setting a maximum number of additional slots that can be booked beyond the slot chosen. This is a setting in the Booking rules tab of Manage courts under an entry entitled Maximum number of additional courts that can be reserved for the same booking. For example, setting it to 2 would allow a member to book a slot and up to 2 extra right at the time of booking (3 slots in total).
There are then two ways to activate extended court booking. But either way, the maximum slots as given above can never be exceeded.
Extended bookings on a court by court basis
There's a tick box in each of the court details popup (in the Court schedules tab) named Allow multiple slots per booking. So, in addition to the setting above, you'll want to indicate to which courts it applies.
With this feature switched on members will be given a choice on how long they want to book for when they either Book with no invitation or Invite others to play when clicking on a slot in the Booking centre. Note that the choice is not given when booking a match directly. Depending on the sport, ManageMyMatch will automatically book out the required number of slots (subject to your maximum) to cover the expected time for a match. For Tennis, for example, this is set to 1 1/2 hours.
Extended bookings on an event basis
An alternative, more granular way to achieve extended bookings is to set an expected match time on an event. This will override the per-court setting above for matches in the name of the event. This is particularly applicable for tennis doubles matches because there is a general expectation to spend more time on court than a singles match.
You can set an expected time in half hourly increments from 30 minutes to 3 hours on the event itself in Manage Series. You'll find the option within the Match configuration panel under the Match section (last section within that panel). If the event is matchless (i.e. it support sessions like coaching) then it'll be within the General features panel. It's called Recommended match/session duration. Leaving this unset will not invoke any extension rule for matches/sessions within this event context. But if a time is set, then a match/session booking will always attempt to book out however many slots as necessary to cover the time - sometimes this may mean booking out more time if the slot times don't necessarily match up. For example, if you set the event to require 1 hour per match and your slot times are 45 minutes, then two 45 minute slots would be booked (1 1/2 hours in total).
In any event, extended bookings can only be made if the slots are free on the same court as the initial booking. Extended bookings never migrate onto a different court