Where i can find the code for CORE - "dropdown" node

I want to create the dynamically growing table like one which is in drop-down node(value and label with add button in drop down node).

where i can find code for core - drop down node in node red

It is ui_dropdown in here - https://github.com/node-red/node-red-dashboard/tree/master/nodes
but it's fairly deeply embedded into the core code. Maybe node-red-node-ui-table would be more suitable ?

Thanks! it works for me