Slightly literary / theatrical.
此 'this',
怎 'how',
讲 'speak/explain' are all classical-leaning, giving the phrase an old-novel or wuxia feel — common in costume dramas and
相声 crosstalk. In ordinary speech use
这话怎么说? (zhè huà zěnme shuō?) or
你这话什么意思? (nǐ zhè huà shénme yìsi?) instead.