What you are looking for is 'Model Explorer'.
You can use the Model Explorer to view, modify, and add elements of Simulink® models and workspace variables. In the Model Explorer, you can get a list of variables that a model or block uses.
The Model Explorer lets you focus on specific elements (for example, blocks, signals, and properties) without navigating through the model or chart.
Take a look at the following link to know more about 'Model Explorer':
The below link specifically talks about 'finding variables used by model':
Hope the above suggestions help :)