When is the upper tone connected before the light tone in the phonetic change of Chinese Pinyin?

The monosyllabic tone value of the upper syllable is 2 14 1. The two upper tones are closely connected, and the previous tone value is changed from 2 14 to 35. For example, the water (2 14-35) fruit 2 is connected with three upper tones, and the first two syllables are semantically compact, and the semantics stop after the first syllable, and then the previous one.