Is there a tool for planning "nested" round trips?

We want to go to Japan. We've checked some flights, and reached an interesting conclusion. First, a normal round trip:

A round trip from Tel Aviv to Tokyo, Sep-26 - Nov-5, costs $880. There are very few "cheap" flights - the fifth option is already at $1146.

But then:

A round trip from Madrid to Tokyo, Sep-26 - Nov-5 (same dates) is as low as $620, with many similar options under $800.
A round trip from Tel Aviv to Madrid, Sep-23 - Nov-8 costs about $300, and there is even a non-convenient flight for $200! (9 hour overnight layover)

So, if I take the cheapest options, I can fly directly to Tokyo for $880, or combine a trip to Madrid and Tokyo for $820 - this is both cheaper and more fun.
Even if I take a "better" flight to Spain it might reach $920 for the combined trip - still well worth it (extra $40).

I've looked and found a similar concept called hacker fare, and also this related question: Is there a flight search engine that combines flights from different airlines?
In my case, unlike hacker-fare, I want two round-trips, and I don't particularly care where the "layover" is - it could be any nice city.

Is there a tool that can help me plan such a trip?
For example, showing the two round trips, or showing bulk data to/from popular destinations?

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What is round trip in logistics?

Round Trip also called \u201cround robin\u201d a round trip is where a driver moves a load to a point, reloads at that point, and returns with a load back to the original point of pickup. Round trip loads are usually priced at a discount since the driver does not incur any deadhead cost once he delivers.

What is round trip with example?

Round-trip definitionA trip from one destination to another and then returning to the starting location. Margaret purchased a single round trip ticket to and from Chicago, as it was cheaper than buying two one-way tickets. A trip from one place to another and back, usually over the same route.

Why is it called a round trip?

A round trip is the term for a journey for travels from one location to another and then back again to the original starting point. A common abbreviation for a round trip in the travel industry is R/T. The standard opposite of a round trip is a one way.

What does a round trip do?

A round trip, as the name suggests, means traveling from one point to another and then returning back to the same starting point, usually via the same route. This is considered to be a better way of booking tickets, if you have a fixed schedule, rather than booking two separate one-way tickets.

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