Issue: Nested Mustache variables not being parsed correctly

[k3vob]

Issue you'd like to raise.

I have a prompt in the following format:

{{#is_a}}
In A
{{#is_b}}
In A.B
{{b}}
{{/is_b}}
{{/is_a}}

1. In the Prompt playground, you can see that is_b was recognised as it is blue, but b was not as it is still black.
2. In the variables on the right, you can see that only is_a was found.

I see the same when I pull this prompt and print it:

input_variables=['is_a'] metadata={'lc_hub_owner': '-', 'lc_hub_repo': 'temp', 'lc_hub_commit_hash': '463e2203cb19e084cc661be7b2f44f088d9f3d8ddb488ecb4d3be02ac3e49134'} messages=[SystemMessagePromptTemplate(prompt=PromptTemplate(input_variables=['is_a'], template='{{#is_a}}\nIn A\n{{#is_b}}\nIn A.B\n{{b}}\n{{/is_b}}\n{{/is_a}}', template_format='mustache'))]

Suggestion:

Nested Mustache variables should be parsed correctly.