The best way to see the context surrounding a task is to include a backlink within the task, using the Note Linking creation syntax.
linkIncluding one section of the note as context
If you want your task to include as context a particular section of a note, here's how to do that.
Document how to view a section context from within a task Including one section of the note as context
Here is a quick video showing the creation of that backlink. It's pretty simple: you can just use the @ and then hit # to get a list of all the sections from the note, choosing the section that you'd like to include.
linkIncluding the whole note as context
If you'd like to view the entire note within your task, it's a similar process. Just use [[ and enter the title of the note:
Document how to view an entire note: Demo: Include a backlink within the task
The title of this note starts with "Demo" so to create that backlink, I hit [ twice, typed "demo" and hit enter. After you create the backlink, you can always edit its text if you don't want your task to include the entire name of the note, a la:
Document how to view an entire note: Like so