Hi Abeks, 

You are unlikely to find a document template that is deliberately High Level. Instead, I would suggest that you start off with a standard template, (which one rather depends on the methodology you are using) and start completing that, but the requirements are at a High Level stage. 

In other words, complete the Requirements section, but just with High Level information. You can then send that out to your stakeholders if they need to endorse it, and you can work on the same document as you get to more detailed Requirements gathering - just by overwriting or adding to the High Level Requirements already entered.