Yes, den här takes the definite: ’det här laget’, but detta takes the indefinite: ’detta lag’ and the latter is more formal. However, in southern and western Sweden, you can also say detta laget which is equal to det här laget in speech, but you can write det här laget but not detta laget. As a summary:
- Det här laget: spoken and written form.
- Detta lag: primarily written form, not used much in speech.
- Detta laget: only spoken form (dialectal).