I want to add a field like below image in my custom module. My admin form content resides in the block class. How to achieve this?

enter image description here

closed as unclear what you're asking by Fabian Schmengler, Fiasco Labs, hellimac, Keyul Shah, Qaisar Satti Jan 18 '16 at 4:11

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.