What are examples of Hindu philosophy or practice being influenced by Christian thought, tradition, or practice (e.g. the Brahmo Samaj)?
Hinduism was not influenced by Christianity, rather it predates it. The 2 religions have completely incompatible world view.
There has been lots of effort put on by European Indologists to paint Vivekananda & Ramakrishna Mission to be copying Christian values of service & charity.
The Book Indra's Net proves with philosophical & historical evidence that Vivekanda's ideology of seva originated from the Upanishads & not from Christianity. The basis of Seva(service/charity) is "Tat Tvam Asi" principle which means "you are that". You are same as your neighbor. The basis for this philosophy predates Christianity.
There is a fundamental difference in religious styles of the West and the East.
Western religions (Islam and Christianity) have a digital view of the world. Creator and Creation.
Hinduism in its core believe the Created and Creation are one and the same.
Western religions believe in preaching. Hinduism believes in understanding and experiencing.
Western religions have this view of "Not my way, or the highway". Hinduism treats "My way", "Highway", "Some other way", "No way" as different ways.
Western religions could have been influenced by Hinduism, since the texts and scriptures existed at the time the Western religions came up. Hinduism is unlikely to have been influenced by Christianity.
Cultural influences of the West on the East, did occur, but religious influences were very limited, as the two religions have markedly different styles of approach towards God.
Hinduism has vast literature and every component of "universe" is explained in detail and to go through such literature, one requires many births and then to understand it many many more.
Christianity & Islam are preachings of a single person i.e. single awakened person, within a very very limited life span
To make mountain of such preachings and to talk of "entire universe" with a single book, is far fetched. Gita is also a small book, however, the depth of sacred text mentioned in GITA is far superior to Bible and / or Islam.
Nothing in Hindu society nor practises of any hindu individuals is influenced either by Christianity or Islam.
Saint / Sage Ramanuja himself "converted" shudras to brahmin, saying there is no casteism defined in hinduism (i.e. no cultural discrimination of any type)