Filter time metadata fields with variables in knowledge database

[pr-maia]

Self Checks

• I have searched for existing issues search for existing issues, including closed ones.
• I confirm that I am using English to submit this report (我已阅读并同意 Language Policy).
• [FOR CHINESE USERS] 请务必使用英文提交 Issue，否则会被关闭。谢谢！:)
• Please do not modify this template :) and fill in all the required fields.

1. Is this request related to a challenge you're experiencing? Tell me about your story.

Having the possibility of using variables to filter fields in the Knowledge Retrieval node is great. It'd be even better to be able to filter time based on variables as well.

This way i could run the query restricting the results to only time-relevant documents.

2. Additional context or comments

No response

3. Can you help us with this feature?

• I am interested in contributing to this feature.