Maps in string representation in Сontext

[s666p]

Hello. Could you please tell me, is it possible to put Maps in the context as a string so it would be possible to access values by keys in expressions? If so, how do I do it?

For example, let's look at the sample context:
key1 -> { a: 's1', b: 's2' }
key2 -> {{ key1.a }}