That’s only for UAS weight over 7kgs.
For our hobby drones (well most of them) the drone has to be in VLOS and the pilot capable of seeing the drone and any obstacles around it.
So taking off from top of hill/valley, as long as you can see the drone and what is around it, you are doing nothing illegal
Please see the following source: http://www.legislation.gov.uk/uksi/2016/765/article/94/made