Interesting and Hidden Aspects:
This question abbreviates the earlier verse in Luke 13:18 using the same words and forms, but this is hidden by translation. This is an example where the English words changed to make it look to English readers as though Jesus is not repeating himself when he clearly is. Interestingly, this verse is made to look more like Mark 4:30, which it does not resembles as closely. These changes occur in the first two words, so it is very instructive to see how misleading translation can be.
The word translated as "Whereunto" means primarily "anything" or "anyone," but Jesus often uses it to start a question so it means "who", "what", or even "why". The form is that of a comparison. In Luke 13:18, the same word in the same form is translated as "unto what", which is closer to its meaning. However, in Mark 4:30, a completely different Greek word is translated as "whereunto".
The verb translated as "shall I liken" is a verb that means "to make like" and, in the passive, as used here, "to become like." The form could be the first person as translated or it could be the second person, "compare it for yourself?" In the earlier Luke version, the same word in the same form is translated as "shall I resemble". In the Mark version, the same word is offered in a different form but translated in a more similar way, "shall we liken".
The phrase, "kingdom of God" is used more commonly in Luke than the "the kingdom of heaven" generally used in the other Gospels. It discussed in more detail in this article.
The word translated as "kingdom" can be the region, the reign, the castle or the authority of a ruler. Christ does not seem to use it to mean a physical region, so its translation as "reign" or "realm" seems more appropriate. This is especially true because the "reign" of a king means the execution of his will.
The word translated as "God" means "God" and "deity." It is introduced with an article, so "the God" or "the Divine". Jesus often uses it this way perhaps to indicate the uniqueness of God as opposed to the pagan gods.
Τίνι (irreg sg dat) "Whereunto" is tis which can mean "someone", "any one", "everyone", "they [indefinite]", "many a one", "whoever", "anyone", "anything", "some sort", "some sort of", "each", "any", "the individual", "such," and so on. In a question, it can mean "who", "why," or "what."
ὁμοιώσω (verb 1st sg aor subj act or verb 1st sg fut ind act or verb 2nd sg aor ind mid) "Shall I resemble" is homoioo, which means "to liken," "to compare", "to make like", and and in the passive, "to become like".