The positional adverbial 在+NP loc ‘zài + NP loc’ phrase can readily assume the role of a sentential adverbial which relates to the sentence as a whole rather than solely to the verb and post-verb constituents. A sentential adverbial has the relative freedom to occur in the initial position of a sentence. Consider:
Zài yuètái shàng mǔqin zài nǚer de miànjiā shàng qīnwěn le yíxià.
(On the platform Mother kissed her daughter on her cheek.)
1b. ?母亲在月台上 在女儿的面颊上 亲吻了一下。
? Mǔqin zài yuètái shàng zài nǚerde miànjiā shàng qīnwěn le yíxià.
(Mother kissed her daughter on the cheek on the platform.)
*Zài nǚer de miànjiā shàng mǔqin zài yuètái shàng qīnwěn le yíxià.
(Int: *On her daughter’s cheek the mother kissed her daughter on the platform.)
Zài yuètái shàng, mǔqin zài nǚer de miànjiā shàng qīnwěn le yíxià.
(On the platform, Mother kissed her daughter on her cheek.)
The sentential adverbial, compared with the predication adverbial, is relatively peripheral; while the predication adverbial, as it denotes the exact location where the action named by the verb is carried out, must be ordered just prior to the verb in accordance with Haiman’s distance motivation. So (1c) is unacceptable, another reason for its unacceptability is that the adverbial 在女儿的面颊上‘zài nǚer de miànjiā shàng’ (on the daughter’s cheek) denotes a smaller scope compared with the other one 在月台上‘zài yuètái shàng’ (on the platform), hence it cannot function as a sentential adverbial modifying the entire sentence. (1b) is not preferable, because two identical adverbials of position are placed side by side. The sentential adverbial, which applies to the whole sentence, can be placed in the initial position, somewhat distant from the predication; what’s more, it can be separated from the rest of the clause by a comma, as shown by (1d).
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.