Every maf'ul bihi here is mansub, but its sign depends on the form of the noun.
Object formExampleSign or statussingular or broken pluralالتُّفَّاحَ، مَحْمُودًا، الْكُتُبَfathahsound masculine pluralالْمُسْلِمِينَyasound feminine pluralالسَّمَاوَاتِkasrahmabni relative pronounالَّذِينَin the position of nasb
First identify the role; then name the sign that suits the noun.