Run your cable from the first light to the second light. Sparky channel 6494 views.

How To Replace A 2 Gang Double Light Switch
How to wire a double light switch to two lights. Connect the three ground wires together along with a pigtail with a wire connector wrap it with electrical tape and stuff it back into the box. Wrap a piece of black electrical tape around each end of this white wire to indicate that it is a hot wire rather than a neutral wire. It is one black wire from the power source hot wire and a black wire from the neighboring switch. Powering a double switch controlling two separate light fixtures from a single power source isnt a casual diy project unless youre confident of your skills. The hot wire pathway is now complete from power source cable through the switches and on to the light fixture locations. Double switch test and replacement for bath fan and light in a 1960 house duration.
Pull one end of each cable through the back of one of the light fixture electrical boxes. The source is at the switch box and a 2 wire cable is run to each light. Connect the black wire from the switch to the black wire from the first light and the black wire coming from the second light. That is one light done. Wrap it clockwise around the screw terminal and tighten securely. Connect the red from the other end of the cable to the loop terminal thats your live feed back to the switch.
Now youll need a piece of two core earth cable to run between the two light fittings. Look at the terminals on the double gang switch. Form a c shaped loop in the stripped end of the wire. Run 12 gauge electrical cable between each switch and the light it controls. Strip both ends of each cable. How to wire two light switches with one power supply.
Connect the pigtail to the ground screw on the double gang switch. Connect the blue wire to the l terminal on the light fitting. On one side you should see two screws connected by a small piece of metal. Connect one of the black wires running from a light fixture cable to each of these screws. One source is spliced to each switch with a pigtail to power the two lights. Wiring two switches for two lights here two switches are wired in the same box to control two separate lights.
Connect the one black wire to the bottom dark screw of the other already wire configured switch. Essentially 2 black wires are attached to the bottom dark screw of one switch.