Hello Juan Pablo:

In this case, it is difficult to find the best answer because the original sentence in Spanish has not a clear end. It finished in mid-word.

What really is this mid-word?

FIRST OPTION:

Possible term: “entre”. But “entre” is Spanish is preposition.

Normally, in a sentence, a preposition is a relation-word between an “antecedent” and “object”. Here we don’t see the “object”.

If we assume that the missed part is: “entre ellos” we can write the original sentence in this way:
“La técnica permite establecer grupos homogéneos internamente y heterogéneos entre ellos.”

What this sentence means? It means that the technique divide a community, company, school or country in different kinds of groups that are mixed. But like DLyons says: “it's not clear what's heterogeneous.”

Assuming there are two kinds of groups: A (homogeneous) and B (heterogeneous), we can translate the modified Spanish sentence to English in this way:

“The technique allows the establishment of homogeneous groups internally and heterogeneous in between.”

SECOND OPTION

Possible term: “entrecruzados”. For example: “La técnica permite establecer grupos homogéneos internamente y heterogéneos entrecruzados.”

In this case, a possible translation would be: “The technique allows the establishment of homogeneous groups internally and heterogeneous crossed.”

THIRD OPTION

Possible term: “entrelazados”. For example: “La técnica permite establecer grupos homogéneos internamente y heterogéneos entrelazados.”

In this case, a possible translation would be: “The technique allows the establishment of homogeneous groups internally and heterogeneous interlocked.”

FOURTH OPTION

Possible term: “entremezclados”. For example: “La técnica permite establecer grupos homogéneos internamente y heterogéneos entrelazados.”

4.1. In this case, a possible translation would be: “The technique allows the establishment of homogeneous groups internally and heterogeneous mixed.”

4.2. In this case, a possible translation would be: “The technique allows the establishment of homogeneous groups internally and heterogeneous combined.”

SUMMARY:

We can imagine more Spanish words that begin with “entr” but after we reviewed the vocabulary included in the Dictionary of the Real Academia Española, the best options are:
- Spanish preposition “entre”
- Spanish verb “entrecruzar” in the particle past used as adjective = in English “crossed”.
- Spanish verb “entrelazar” in the particle past used as adjective = in English “interlocked”.
- Spanish verb “entremezclar” in the particle past used as adjective = in English “mixed”, “combined”.

I hope this analysis helps you in your work.

Regards

Domingo

NOTE: Sources used in this analysis:
1) Diccionario de la Real Academia Española
2) Collins English Dictionary
3) Collins English Spanish Bilingual Dictionary
4) The FreeDictionary by Farlex