It was part of a Nazi plan called "Lebensraum" where people of the wrong ethnic group would be killed, those of slightly wrong groups would be enslaved and those of the correct group would be indoctrinated into Nazi values.
All vaguely steaming from looking at British, French and Spanish colonies were large numbers of their ethnic groups had taken hold.
Also in the '30s Italy invaded Ethiopia and Japan invaded Manchuria to create belated empires though with less overtly genocidal intentions.
(However dry the above description, I personally do not want to suggest that the Nazi project is equivalent to those other nation's actions)
All vaguely steaming from looking at British, French and Spanish colonies were large numbers of their ethnic groups had taken hold.
Also in the '30s Italy invaded Ethiopia and Japan invaded Manchuria to create belated empires though with less overtly genocidal intentions.
(However dry the above description, I personally do not want to suggest that the Nazi project is equivalent to those other nation's actions)
[1]https://en.wikipedia.org/wiki/Reichskommissariat_Ukraine [2]https://en.wikipedia.org/wiki/Lebensraum