Group by a Thing's Thing?

I have 3 things involved in the bar chart I am trying to populate. )Job Types, Jobs and Transactions. And, am trying to build a bar chart which graphically demonstrates the sum of all transactions grouped by their corresponding job’s job type.

Transactions: Amount, Date, Job (and several other fields)
Job: Date, Job Type (and many other fields)
Job Type: Title (and many other fields

What I would love to do is run a search for transactions that have come in within the last year, and put it in a bar chart broken down by the Job type. I’m familiar with grouping data but I haven’t figured out how to accurately group by a thing’s thing. Meaning, grouping transactions by their job’s job type.

The grouping label would be Job Type’s Title and the value would be the sum of that grouping’s transaction amounts.

Any idea how to accomplish this?