This solved my problem. I am not able to create it in the GUI though.
Thing mqtt:topic:snzb01a "My Awesome Button" (mqtt:broker:e90f42a7f8) @ "Some Fancy Room" {
Channels:
Type string : action "Action" [ stateTopic="zigbee2mqtt/0x00124b0022697442", transformationPattern="REGEX:(.*action.*)∩JSONPATH:$.action"]
Type number : linkquality "Link Quality" [ stateTopic="zigbee2mqtt/0x00124b0022697442", transformationPattern="JSONPATH:$.linkquality"]
Type number : battery "Battery" [ stateTopic="zigbee2mqtt/0x00124b0022697442", transformationPattern="JSONPATH:$.battery"]
Type number : voltage "Voltage" [ stateTopic="zigbee2mqtt/0x00124b0022697442", transformationPattern="JSONPATH:$.voltage"]
}type or paste code here