I want to create an item in one board from a status change in a subitem in another and link them.
I can add connected board fields at a subitem level and also mirror a status field but when I write the create an item based on subitem status change and link automation I can only see the connected board at item level.
I would also like to see this functionality happen. It would be super handy, especially since the correct columns and automations etc. are already available to use for it.
I use this process in joinery manufacturing and sub-items are used for products needing to be ordered that are specific to a job. When we assign a supplier via status to a sub-item, it creates a new item on our purchases board but needs to be link backed so that we can track it’s arrival status from the main board as well.
Currently I can still achieve this by manually selecting the sub-item that I would like to link, but it is a tedious process doing it for every item. As I touched on earlier, considering the columns and automations are there, and the fact that I can manually make the link after the item is created, makes me think it should be fairly straight forward feature to implement.
Hi @Laura.Abbott ~ Welcome to the Community! 
As you’ve noticed, our subitems are currently still in Beta which is why some core functionalities are still missing, such as full support in automations. Our developers are working hard on adding and enabling upcoming features as soon as possible, but to be fully transparent they will be coming in increments as we want to ensure that each functionality is released with the best quality possible.
You can always keep up with the roadmap for subitems here - however, please note that while this information is shared to outline some of our plans, these plans are subject to change.
I’ve changed your post into a Feedback Post so that other members of the community can also Vote for this ability to be added and share why it would be helpful for their teams! Our product team takes user feedback very seriously! In fact, many of our features began as user requests 
Cheers,
Jenna
I second this post. This function will reduce a lot of manual work for our users and keep the high level boards what they’re meant to do: fast and clean overview of all projects.
We can already connect subitems with an item in different boards and mirror their status, but the automation still doesn’t connect it, you have to do it manually.
Looking for an update on this! I need to link/mirror a subitem on another board so when changes are made, they are reflected accurately everywhere. This would be hugely beneficial to my team
This would be a great feature, especially when setting up inventory list linked to orders with products. I would like to be able to automate “create item in another board & connect subitem with item”. Hoping to see this feature soon!