I believe what you're asking is: "Is there any way to create just one helm chart that can be used for all microservices in my application?". If so, then you can just use the values.yaml file to store all the values for your templates. This is not considered good practice, considering your template file needs to hold the information for each of your microservice deployments (and thus will become really difficult to manage), but it is possible.
One example: say you have two microservices, and you need one Helm chart that will create the template for both microservices. Generally, you would create separate templates for each service under the templates folder, and deploy each Helm chart for each service individually, but instead you could create multiple deployments in one template yaml file, like
# For service 1
etc., etc... (stick in all values.yaml file values here for service 1)
# For service 2
etc., etc... (stick in all values.yaml file values here for service 2)
In your values.yaml file, you would then just place in the values for each of your services, like
# Service 1 Keys/Values
# Service 2 Keys/Values
So to answer your question, you can package all your services into one individual Helm chart using the above method, and Kubernetes will run each service as their own ReplicaSet as expected. However, when you have many services to manage, it can be tricky to manage the template YAML files and the values.yaml files when you put in values for all your services in one file, and so it's most likely not a good practice to do this.
This is just my understanding of Helm so far, as I'm still learning Helm myself. As such, I'm not 100% sure if this can be done, so you might want to double check with another person that this answer is actually correct.
EDIT: To summarize: like I mentioned above, in theory, it is possible to use one Helm chart per service. But in practice, it will be extremely messy later on to manage the values.yaml and the templates in the templates folder. So the answer would be, "Yes in theory, but not recommended at all".