If you ever wonder how to do this is the exact time to figure it out together.
These are types of user inputs you can pass to a child flow:

What I was doing previously is passing a record ID as a Text input parameter then I was querying data using this ID. Like this:

But if you query data in a parent Flow already or if you want to pass data from a trigger context …
Let’s say I found a much better way. It has got one tiny disadvantage which I will flag later. But in general, it’s a valid option.
I would like to pass a trigger context from the parent Flow to a child. I will pas it as Text but will JSON.
Calling from the parent Flow:


Because in the trigger output we’ve got the context in JSON format:

Then in the child Flow we add Parse JSON action and copy OUTPUTS body JSON from the parent Flow to the Generate from sample:

Now you’ve got properties from your parent Flow available in the child Flow:

As I promised the disadvantage. As you can see it on the screen it only gives you attribute names not proper display names. But if you with it then you can use this approach to pass more data.
Simple!