[1] According to one common definition, it is any position that has responsibility for "cash, keys, or kids (minors)".
A typical position of trust at the personal level involves child custody or power of attorney.
Any regulated profession dealing with the health and safety of others usually requires certification and licensing and would be a position of trust.
The same would be true in the hierarchy of relationships involved in education, employment, financial matters and government.
[5] Similarly, molestation by a person in a position of trust is also a criminal offence in Singapore punishable by imprisonment.