M4250 switch connecting to different layer3 switch

We recently purchased the streaming equipment; Netgear M4250 switch, Cannon 4K PTZ cameras and other equipment for streaming purposes. All equipment is on a trolley and it works great. The original plan was to be able to also be used in a room connecting to the nearest sub-switch and the cameras are positioned down at the lawn bowl greens connecting to another sub-switch which already trunk via fibre cable to the core switch in a different location. How do we go about making the M4250 to be configured to work with our environment or vice versa?

The attached visual diagram is what we had in mind - but we didn't realise the M4250 is required.