Relationship between 3 tables connecting with one variable

[Jordi007]

Hi colleages from Qlikview, i'm having a problem that I'm not sure how to solve. 

The problem:

I have a database from a softaware built by insiders of a company. I'm building a dashboard where i want to filter by "Driver name". 

First, I have a table where it shows many data and one column it shows the drivers, and the content is driver one, driver two... And it's connected to another table where is the driver name. So driver one is Juan, driver two Manuel... 

At this moment this is easy, but here is where it gets complicated. I have another principal table that gives me different info where it shows also driver, and it's connected to another table where it says driver one is ManuelG. , driver two Jesus A.... 

So driver two from principal table 1 and driver one from principal table two are the same, I want it to filter by these name when extracting data from both principal tables but I don't know how to connect this variable.  Also, they are writted diferent so Manuel it's the same as Manuel G.

Principal table one
Date	Route	Driver
01/01/2021	X	1

Drivers
Driver	Driver name
1	Juan

Principal table two
Date	City	Driver
01/01/2021	X	2

Drivers
Driver	Driver name
2	Juan G.

Resume: I want to qlikview to understand that Juan is the same person as Juan G. when filtering by drivers name.

[Or]

You could use Subfield([Driver Name],' ',1) to get just the first name.