https://www.drupal.org/project/business_rules/issues/3089784#comment-14…
It took a bit to work out so I though I would post here the steps to do this for anyone else:
1. In Views create a view of users and add the email field to the view. In my case I created a block view of this and I put a filter in this view to only display users of a certain role.
2. In Business Rules click on the Variables tab and add a new Variable View Results Variable and under View to execute. View name : Display mode id : Display mode title. Select the View that you just created in step one in my case I selected the block view not the master and save.
3. Create an action Send Email and in the TO Field you can select a variable that you find further down the page under Available Variables for this context: in the table you see your View Result Variable and under Description of that row you can "Click here to see the view fields" and find your email field token. Copy this into the TO Field. Save this action.
4. Create another action of type "Loop through a view result variable" and under "Select the view result variable" select your view. In "Items to execute during the loop" click add an action and select the action you created in step 3. Click save.
5. Create a Rule and now you can use the "loop through a view result variable action" in this rule and it will send out the email to all users in the view.
----
In my case I used it in a condition as I only needed to sent the email if a certain condition was present.
Thank you @lexsoft for pointing me in the right direction.