Selling just a commercial building on my land. NO Land included?

[Thomas Eigner]

I have 2.71 acres of land that a mobile home park and commercial building sits on. The commercial building previously was leased out but that contract expired this year. 

The restaurant is in front of the park with both sides of the restaurant entrancances to the mobile home park. The Park makes a U behind the restaurant with another row of lots down the middle. I attached a picture for better clarification.

The property is all on one plat. I asked the city about separating the two but the city said I can not. The reason is because both business needs separate entrances and exits. They both will have that if separated but that will on paper cause the mobile home park to now make a hook with a dead end. The argument for them is that the roads won't be wide enough for emergency vehicles to "turn around" in all practicalities the place won't change and emergency vehicles will just continue to go in one way and out the other. 

That is what lead me to the situation that I am in now. I have people wanting to buy just the building, they want the restaurant and nothing to do with the park. I also find investors on the other end of the spectrum who wants the park but not the building. 

A guy I spoke to today wanted me to sell him just the building and exclusive rights to the premises while I retain the land. Is that possible and what is something like that called. Google was vague in my research, he didn't know much about it outside of pitching the idea due to the plat restrictions. He told me to look into it and call him back, anyone heard of anything or know of a way to structure something like this?