Spring boot - @Service class calling another @Service class

It is not any restriction calling a service from another one. Unless you make circular dependency between services.

Circular dependency : https://en.wikipedia.org/wiki/Circular_dependency

Circular dependency in spring : https://www.baeldung.com/circular-dependencies-in-spring

Its good practice since utility class are being ignored these days, approach getting motivated by horizontal scaling... Surely services got to interact with other.

No need to worry, its like one service manager needs services of another manager.

just only one should be dependent on other, not both.